Modified neurotoxin

ABSTRACT

Neurotoxic snake venom is detoxified, e.g., by oxygenation, to form an atoxic, neurotropically active therapeutic composition. The venom must be at least in part derived from the genus Bungarus, but preferably also contains venoms from the genus Naja or Crotalus terrificus terrificus. The composition will mitigate the progress of degenerative neurological diseases by blocking nerve cell receptors.

United States Patent [191 Sanders June 10, 1975 MODIFIED NEUROTOXIN [76]Inventor: Murray J. Sanders, 3009 Spanish Trl., Delray Beach, Fla. 3344422 Filed: Feb. 1, 1973 2! Appl. No.: 328,724

52 us. Cl. 424/98 [51] Int. Cl A61k 27/00 [58] Field of Search 424/98[56] References Cited OTHER PUBLICATIONS Chem. Abst. (I), Vol. 74,305l2p, (1971). Chem. Abst. (2), Vol. 84, 20440c, (1966). Chem. Abst.(3), Vol. 59, 12072f, (1963). Chem. Abst. (4), Vol.55, 20198g, (1961).

Chem. Abst. (5), Vol. 55; 6685gh, (1961).

Primary Examiner-Stanley J. Friedman Attorney, Agent, or FirmCushman,Darby & Cushman [5 7 ABSTRACT 22 Claims, N0 Drawings MODIFIED NEUROTOXINThe present invention relates to a composition, a process of productionthereof, and a method for treatment of neurological diseases andespecially to the treatment of heretofore intractible diseases such asamyotrophic lateral sclerosis.

BACKGROUND OF THE INVENTION Degenerative neurological diseases progressin a chronic manner to severe physical disability, such as paralysis,and even to death. While the cause of such neurological diseases is notalways known, many of the diseases are results of specific infections,e.g., viral infections. It is believed that the specific viruses causingthe specific neurological diseases attach to or function in conjunctionwith nerve cell receptors of the motor cells of the central nervoussystems. Some workers in the art believe that these nerve cell receptorsare discrete anatomical structures of the nerve cell, while othersbelieve that the receptors are theoretical biophysical concepts whichdescribe one of the functions of the nerve cells. Irrespective oftheory, it is well known that nerve cells do act in a manner as ifphysical receptors exist in the nerve cell. It is further believed inthe art that viral caused neurological diseases function, at least inpart, through viral impairment of the nerve cell receptors and eventualdestruction of the nerve cell. In any event, the affected nerve cellscease to function as healthy cells. These affected nerve cells may beconsidered to include a range of abnormal conditions varying from apartially damaged and therefore reversible state to a totally destroyedor neuronophagic state.

Many of the degenerative neurological diseases progress in a subtle andinsidious manner to slowly cause impairment of the victim. Thus, thediseases are often overlooked in the early stages by the skilledclinician and the disease may progress to a point where mild paralysis,or fasciculation (twitching) of the muscles or other early symptomswhich are specific to the disease being observed occur. Of course, atthis point many nerve cells have been adversely affected and thosecells, as noted above, cease to function in the normal manner. Whilevarious known chemotherapies can have some beneficial effect in treatingsuch disease, most often the disease proceeds through increasedparalysis and involvement of the pyramidal tracts causing loss ofbalance and like disorders, even to bulbar involvement and eventuallydeath. For many of these diseases, the prognosis is most unfavorableindeed. Among such diseases of the central nervous system areamyotrophic lateral sclerosis, multiple sclerosis, kuru. acutepoliomyelitis, etc. Since known chemotherapies. at best, only slow theprogress of the disease, these therapies are not cures but only delay,essentially, the effects of the disease. It would, therefore, be ofsignificant benefit to provide a therapy for treating such degenerativediseases of the central nervous system.

OBJECTS OF THE INVENTION In view of the above, it is an object of theinvention to provide a composition and therapy for treating progressivedegenerative diseases of the nervous system which involve the functionof motor nerve cells from their origin to the neuromuscular junction, aswell as elements of the central nervous system including axones, nervemyelin sheaths, etc., such as amyotropic lateral sclerosis, multiplesclerosis, kuru, polymyositis,

certain meningitides, muscular dystrophy, polyomyosi-- ties and thelike. It is a further object of the invention to provide a compositionand therapy for the treatment of diseases of the aforementioned type,which composition and therapy are safe, effective and may beadministered over long periods of time. It is a further object of theinvention to provide a method of manufacture of the composition of thepresent invention. Other objects will be apparent from the followingdisclosure and claims.

BRIEF STATEMENT OF THE INVENTION It has now been discovered that certainmodified neurotoxins have the ability to, apparently, attach to orotherwise involve motor nerve cell receptors and mask or block thosereceptors from attachment or involvement with pathogenic organisms,viruses, or proteins with potentially deleterious functions. Themodified neurotoxins are derived from venoms of certain genera of snakesand are prepared by detoxification of the toxic portions of the venomswhile maintaining the neurotropic character of the resulting detoxifiedportion of the venoms and the remainder of the venom components.Conveniently, the venom is detoxified by controlled oxygenation,although any of the known detoxification procedures may be used with theexception of certain methods used to produce antivenom. The detoxifiedvenom is then stabilized for storage. The present composition may beproduced from any snake venom which acts, essentially, as a neurotoxin,as opposed to, essentially, a hematoxin. However, as will be more fullyexplained below, the composition must be derived from venom which is atleast in part a broad central nervous system cell penetration venom suchas obtained from the genus Bungarus.

DETAILED DESCRIPTION OF THE INVENTION The present composition isprepared by the con-' trolled detoxification of, at least in part, broadpenetration neurotoxic venom. In this regard, it should be appreciatedthat the venom of most snakes have some neurotoxic and some hematoxiccomponents, but the various genera of snakes can be essentiallyseparated into a first group, the venom of which functions, mainly,through interference with blood chemistry and a second group, the venomof which functions, mainly, through destruction of nerve cellcomponents. The former of these genera, i.e., the hematoxic venomsnakes, is represented by the common North American pit vipers, such asthe rattlesnake, copperhead and water moccasin. The latter of thesegenera, i.e., the neurotoxic venom snakes, is represented by the cobra,krait and coral snake. However, there are degrees of distinctionsbetween these two groups. For example, the venom of the North Americanrattlesnake is almost completely hematoxic, while the venom of theCentral American rattlesnake is hematoxic, but yet has significantneurotoxic components. On the other hand, certain species of SoutAmerican rattlesnakes, especially the Crotalus terrzflcus terrificus,has venom which is extremely neurotoxic. At the extreme, the venom ofthe krait, e.g., blue krait, is such a broad penetration neurotoxin thatinvolvement of the central nervous system is extensive and survivors ofthe bite of that snake are extremely rare. For purposes of the presentspecification, the term neurotoxic snake venom is defined as snake venomwhich is toxic to mainly, but not exclusively, the nerve cells andancillary components as noted above.

The venom of snakes contain a multitude of chemical compounds, includingvarious enzymes. The exact function of enzymes in the venom is notunderstood and, indeed, the enzymes may not have any direct function inthe toxic effect of the venom. The enzymes may have other functionsbeneficial to the snake in utilizing the victim of its bite for food.For example, it is known that the body of an animal killed by snake bitewill decompose more rapidly than that of other deaths. It has also beenfound that the higher molecular weight compounds of cobra venom, as canbe separated by chromatography, are not significantly toxic, while thelower molecular weights are highly toxic. Irrespective of the specificcompounds in snake venom, the present composition is preferably producedfrom whole venom which will, of course, include the enzymes although itis recognized that many of the components of the venom are inert forpresent purposes and could be separated from the active portions of thevenom. Thus, while whole venom is preferred for this specification snakevenom is to be construed as the whole venom or the toxic portionthereof. This definition is also inherent in the terms snake venomneurotoxin".

While not being bound by theory, it is believed that the presentcomposition functions by attaching to or involving the nerve cellreceptors to such an extent that the receptors are unavailable forattachment or involvement by neurological bacteria, viruses or proteinswith potentially deleterious functions, thus halting the progress ofdegenerative nervous system diseases. It should be clearly understood,however, that the present composition is not prophylactic and will not,therefore, prevent or destroy a viral infection. The effect of thecomposition is considered to be that of a cell-receptor blocking agentwith absorption and excretion by the cells which, therefore, requiresdosing until the invading causative agents are lost by the immuneresponse of the body or disappear by way of natural attrition due tolack of cellular nutritional factors essential to maintenance of theinvaders existence. Accordingly, continued treatment with the presentcomposition may be required for long periods of time to ensure that thenerve cell receptors are continuously blocked from involvement with thecausative agents of the disease.

The studies of Lamb and Hunter (Lancet 1:20, 1904) showed byhistopathologic experiments with primates killed by neurotoxic Indiancobra venom that essentially all of the motor nerve cells in the centralnervous system were involved by this venom. A basis of the presentinvention is the discovery that such neurotropic snake venom, in anessentially non-toxic state, also will reach that same broad spectrum ofmotor nerve cells and block or interfere with invading pathogenicbacteria, viruses or proteins with potentially deleterious functions.Thus, for the foregoing reasons, the snake venom used in producing thepresent composition must be a neurotoxic venom, as defined above.Further, since the dosages of venom required to block the nerve cellreceptors would be far more than sufficient to quickly kill the patient,it is, of course, imperative that the venom be detoxified. On the otherhand, since the essential components of the venom must remain intact sothat the venom will involve the nerve cell receptors and effectivelyblock the receptors from bacterial, viral or potentially deleteriousprotein involvement, it is likewise imperative that the detoxificationof the venom not denature or otherwise adversely degradate the venomcomponents. Thus, for purposes of the present invention undenatured, butdetoxified venom must be used. The undenatured venom is referred toherein as being neurotropic.

In order to accomplish detoxification of the venom in accordance withthe foregoing required conditions, the venom is preferably detoxified inthe mildest and most gentle manner. While various detoxificationprocedures are known to the art, such as treatment with formaldehyde,fluorescein dyes, ultraviolet light and the like, it is preferred thatgentle oxygenation at relatively low temperatues be practiced, althoughthe particular detoxification procedure is not critical. Quite suitablya modified Boquet detoxification procedure, as explained hereinafter,may be used.

The acceptability of any particular detoxification procedure can betested, most conveniently, by the classical Semliki Forest virus test.The procedure for this test is well known. Briefly explained, a chickembryo fibroblastic tissue culture of cells on glass is overlaid with agelled nutrient preparation such as I-Ianks solution with lactalbumin.The Semliki Forest virus is then inoculated on to the sheet of cells andthe number of resulting plaques show the titer of the virus. If theparticular detoxification procedure practiced with the venom issuitable, then the chick cells can be washed with the detoxified venomprior to inoculation with the test virus and the cells would then showfew or no plaques. If however, a substantial number of plaques isobserved, then the detoxification procedure practiced with the venom istoo severe and unacceptable amounts of denaturization of the venom hasoccurred. Of course, it is preferred that almost no plaques or noplaques at all be observed in this test, although, as will be readilyrecognized, few plaques as compared with the plaques of the unwashedchick cells would be acceptable. The cells washed in the detoxifiedvenom should show at least a statistically significant inhibition ofplaque formation by the virus, e.g., 30%, especially 50% inhibition ofplaques and preferably to inhibition of plaques. As will be alsoexplained hereinafter, suitable concentrations of the present detoxifiedvenom can be determined with this same test. In effect, as can beappreciated, this test shows the ability of the detoxified venom toprevent the proliferation of the viral plaques.

In addition to the Semliki Forest virus test, a bioassay should be madeof the detoxified venom to establish the correctness of thedetoxification procedure used, as well as the potency and absence oftoxicity. Thus, the toxicity of the compositions is tested byinoculation of standard laboratory animals, such as mice, rats andguinea pigs, although dogs and monkeys may be used if desired, andessentially no signs of toxicity should be observed in the experimentalanimals.

If the particular detoxification procedure meets the foregoingstandards, as established by the Semliki Forest virus test and bioassay,it is acceptable for purposes of the present invention. Thus, thecomposition must be a detoxified, neurotropically active derivative ofsnake venom, the neurotropic activity being establishable by theabove-described Semliki Forest virus inhibition test and the neurotropicaffinity being demon strated by patient response to a therapeuticregimen.

As noted above, it is convenient to detoxify the venom by a modificationof the known Boquet technique (Ann. Inst. Pasteur 66:379-396, 1941).According to this procedure, a solution of the venom in a suitablesolvent. especially water, is prepared. While the particularconcentration of venom in the solution is not critical, up to about 3%by weight solution can be conveniently prepared. An antifoam may beadded to the solution, since snake venoms, generally, will causesolutions thereof to foam. Any nontoxic inert antifoam may be used, manyof which are known in the art and particularly, the food grade siliconcompounds. To this solution is added an oxygen-producing compound,although oxygen containing gases, and especially nascentoxygen-containing gases, may be simply bubbled through the solution.Alternately, in situ, oxygen generating mechanisms, such as ultravioletlight or fluorescein dyes may be used to produce oxygen from an aqueoussolution. More conveniently, however, CP hydrogen peroxide (30%solution) is added, along with a catalyst for the activation of thehydrogen peroxide, such as copper sulfate. Since detoxification proceedson the basic side, the pH is adjusted to above 7, but preferably lessthan 10, with a suitable base such as an alkali metal or alkaline earthhydroxide, carbonate or the like, e.g., sodium hydroxide. Alternately,ammonium gas or ammonium hydroxide or other nontoxic amine or likecompound may be used.

Suitably, the solution is buffered at a proper pH with any conventionalbuffer such as an alkali metal phosphate or acetate buffer. If a bufferis not used, or even with the use ofa buffer after longer periods oftime, the pH may tend to drop. Additional amounts of base may be,therefore, required to maintain the proper pH.

The solution is maintained at moderate temperatures e.g., between aboutand 40C, although the upper part of this range, i.e., from about to 40Cis preferred. Temperatures outside of this range may be used, but lowertemperatures prolong the period required for detoxification and highertemperatures can cause unacceptable amounts of denaturization of thevenom. Occasionally, or continuously if desired, the mixture is stirred.After about up to 30 days, especially between 6 and 16 days, under theforegoing conditions, depending upon the temperature and the particularvenom, detoxification will have been accomplished and the venom willhave been modified for purposes of the present invention. Shorter orlonger times may be used, however, so long as the Semliki Forest virustest and bioassay, discussed above, are adequately met.

The detoxification reaction can then be stopped by adding a catalystdeactivator to prevent further action of the catalyst on the hydrogenperoxide. Many such deactivators for the reaction are known, butcatalase (CP) is most convenient for this purpose.

Since the modified neurotoxin produced from the venom will contain ionsgenerated during the detoxification procedure which are neither desirednor effective for the present purposes, it is preferred that these ionsbe removed from the modified neurotoxin product, especially the copperions of the copper sulfate since these ions are somewhat toxic per se.The ions may be removed in any desired way but conventional dialysiswith semipermeable membranes may be used. Thus, the detoxified solutionis simply contained in a semi-permeable membrane, such as celluloseacetate, and the membrane with its contents are submerged in a tank ofphosphate buffer sodium chloride solution, pH 6.8, to cause transfer ofthe undesired ions from the modified neurotoxin solutions of the saltbath. Suitably, this is carried out at room temperature forapproximately one day but temperatures from above 0C up to about 50C for1 hour to 20 days may be used.

The modified neurotoxin is preferably filtered, e.g., through a seriesof graded pore diameter membranes, particularly a series including afinal membrane with a very small average pore diameter, e.g., about 0.22microns, to insure sterility. Prior to the final filtration, preferablya concentration of l/l0,000 merthiolate is established in the product.Merthiolate is a preservative produced by Eli Lilly and Co. Also priorto final filtration, it is preferred to adjust the pH of the bulkproduct to less than 7, e.g., 6.8, by the use of food grade nontoxicacids, such as mineral acids, acetic acid, lactic acid and the like.Here again, a suitable buffer can be employed to maintain the pH on theacid side. The particular pH is not critical, but pHs below 4 are,generally, uncomfortable for certain modes of administration, e.g.,subcutaneous injection, and a pH above 4 and below 7 is, therefore,preferred.

The normal dosage of the present modified neurotoxin fora middle agedmale of approximately lbs. is from 0.7 to 2 ml. of composition producedfrom a 1% by weight solution of snake venom. The dosages arecorrespondingly adjusted for younger or older patients of greater orless body weight. Normally speaking, however, dosages between 0.05 and10 ml. of the composition produced from a 1% by weight solution of venomcan be used, although dosages between 0.4 and 3 ml. are preferred. Thedosages are also correspondingly adjusted for compositions obtained fromother than 1% solution of venom. While a patient may be given themodified neurotoxin as infrequently as every other week, it is preferredthat the composition be administered at least weekly, and preferablyevery other day or daily, e.g., 3 times a week. The composition may beadministered orally, subcutaneously, intramuscularly or intravenouslybut it appears that some of the potency of the composition is lost withoral administration and intravenous administration appears to increasethe possibility of a shock to the body. Thus, either subcutaneous orintramuscular injection is preferred. If desired, for any of theforegoing modes of administration the solution may be compounded intoconventional forms such as tablets, powders, elixirs, and solutions. Inthis regard any of the conventional binders, extenders, diluents,preservatives, etc., may be used. For injection, however, a simplephysiological saline solution or the like is preferred.

As noted above, the composition is not prophylactic and will not destroyor present infection from the pathogenic viruses. Accordingly, thepresent therapy must be continued for an indefinite period. However,continued treatment presents no major difficulty since there is nocontra-indication of co-administration of the present composition withany other drug, other than possibly Vitamin B It appears that Vitamin Bbeing a neuroactive material, somewhat interferes with the function ofthe present composition and, therefore, preferably, Vitamin B is notgiven in conjunction with the present composition. On the other hand, itappears that corticosteroids act synergistically with the presentcomposition and intensify the effect thereof. Accordingly, whilecorticosteroids, such as cortisone, may be co-administered, the dosageof the present composition may be reduced or the patient should beclosely observed in order to detect any undue drug activity.

As discussed above, the venom from which the present composition isproduced must be a neurotoxic venom. However, it has been additionallydiscovered that a portion of the neurotoxic venom must be a broadcentral nervous system cell penetration venom, such as obtained from thegenus Bungarus. The remainder of the neurotoxic venom may suitably be amore specific central nervous system cell penetration venom such asobtained from the genus Naja, such as Naja naja, Naja haja, Naja flava,Naja llalmah and Naja tripudians, although, as noted above, certainneurotoxic species of the genus Crotalus, such as Crotalus terrificusrerrlficus, may be used in this regard. The genus Bungarus isillustrated, especially by Bungarus nullticincrm' and fasciatus. Thevenom of the genus Bungarus has been found to broadly penetrate thecells of the central nervous system and, therefore, a composition madetherefrom can be active toward nerve cells that are essentiallyunaffected by compositions made from other neurotoxic venoms, even otherneurotoxic venoms of snakes from the same family.

In this latter regard, it has been discovered that cobra venom is. asomewhat selective neurotoxin and while a composition made therefromwill protect some cells, especially motor cells, from viral involvement,other cells will not be so effectively protected and viral or othercaused diseases can proceed, although at a much reduced rate andinvolvement. The beneficial effects of cobra venom derived compositionshave been described by the present inventor. See for example, Sanders etal: Antipoliomyelitis Action of Certain Toxoids, Acta Neuroveg. SpringerVerlag in Wien (Based on data presented at the Sixth Symposium ofVegetative Neurology, Strasbourg, France, September 29, 1955); SandersM, et al: Neurotoxoid Interference With Two Human Strains ofPoliomyelitis in Rhesus Monkeys, Ann. NY Acad. Sci 58: 112, 1953;Sanders M: Naja flava Neurotoxoid Interference Late In ExperimentalPoliomyelitis, J Path Bact 68: 1267-1271, 1954; Sanders M, et al: TheRole of Naja flara Toxoid and Toxin in Experimental Poliomyelitis, ActaNeurovegitativa 8: 362-371, 1954; Sanders M, et al: NeurotoxoidInterference in Macac'us rhesus Infected Intramus-cularly withPoliovirus, Science 127: 594-596, 1958; Sanders M, et al.: NeurotoxoidInterference Principle In Pseudorabies Infection, In Vivo, Inactivationof Aujeszky virus, Proc. 7th Inter Cong Microbiol. p.293, 1958; andSanders M: Deceleration of Degeneration of Amyotrophic Lateral Sclerosisin Eight Cases. Proc. Pan Am Med Cong. 1960. All of the foregoingreferences are incorporated herein by reference and all informationtherein is relied upon for disclosure in this specification. Also seeClark, W. B: Supplementary Treatment of Herpes Simplex lnfections of theCornea by Neurotropic Toxoids, Preliminary Report, ConciliumOphthalmologicum Acta, XVIII Congress, Brussels, 1958 and Clark, W. B.:The Use of Sanders Neurotoxoid l (Modified Snake Venom) in the Treatmentof Recurrent Herpes Simplex of the Cornea: Progress Report, SouthernMedical Journal Vol. 55. No. 9. p 947-951, September 1962, both of whichare incorporated herein by reference. The modified neurotoxins of thecobra venom provided substantial benefit but were not capable ofcompletely halting the advancement of many neurological diseases.Further, the modified neurotoxins prepared from the cobra venom, alone,could not be completely detoxified since the potency and desired effectwere thereby lost. Thus, the bioassay could never show completedetoxification and there is, of course, a risk in administration ofapoisonous snake venom which has not been fully detoxified. Also, inthose modified neurotoxins, the entire detoxified solution wasadministered and certain components thereof produced undesired sideeffects in terms of toxicity, other than that of the venom.

As mentioned above, the present composition must be prepared from venomwhich is at least in part derived from a broad penetration venom, i.e.,from the genus Bungarus. While Bungarus venom is similar to Naja venom,the venoms differ with regard to the intensity of the physiologicaleffect and with regard to the time required for the physiologicaleffect. The Naja venom acts more intensely and quickly. On the otherhand, Bungarus venom is not so selective as cobra venom and is activetoward a wider range of nerve cells. Accordingly, the combination ofBungarus venom and Naja venom gives superior results as opposed to Najavenom alone or Bungarus venom alone, although Bungarus venom alone canbe effectively used, as opposed to Naja venom alone, as discussed above.

While the ratio of Naja venom to Bungarus venom is not narrowly criticaland indeed all Bungarus venom could be used, it is preferred that theratio of Naja venom to Bungarus venom be between about 400:1 to 8:1,especially from about to 40:1, on a weight basis.

The invention will be illustrated by way of the following examples butthe invention is not limited thereto but is fully applicable to theforegoing disclosure.

EXAMPLE 1 The following example will illustrate the neurotropiccharacter of neurotoxic snake venoms which are detoxified by a modifiedBoquet procedure.

Type I (Brunhilde) and type II (Lansing) poliomyelitis viruses were usedfor this example. The Brunhilde virus was stored at 30C as a 1:5emulsion in 20% rabbit serum, in non-pyrogenic distilled water. Theemulsion was derived from pooled cervical and lumbar spinal cordenlargements of intracerebrally infected rhesus monkeys showing initialsigns of paralysis. The Lansing type virus was also stored at 30C as 20%mouse brain pools. Mouse intracerebral LD 0s varied between 10*- and 10MUCHCUS rhesus and CFW mice were used as the experimental hosts. Allvirus injections were via intracerebral or intrathalamic routes. Inmonkeys. the test virus was Type I (Brunhilde). The cerebral techniquewas carried out by injecting dilutions of virus pools into the parietalor frontal brain areas of the monkey.

The venoms used were derived from the venoms of the South African cobra,Naja flava, and from the South American rattlesnake, Crotalus terrificusterrificus. The venoms were detoxified by a modified Boquet method.Changes were necessary because of the requirements of the particularneurotoxins. Higher concentrations of hydrogen peroxide (Superoxol-30%hydrogen peroxide) were found moredesirable and the addition of 0.2%formalin was found to be useful for obtaining an improved curve ofdetoxification. Also.

because stability of the neurotoxin was required, it was necessary tomake certain the detoxification reaction was brought to a conclusion.This was accomplished by the addition of catalase, and by changing theslightly alkaline pH of the solution to pH 6.8 at the time catalase wasadded. The change of pH is necessary since detoxification continues tooccur within the alkaline range.

40 grams of desiccated Naja fluvu are placed in a flask and about 3,800ml of phosphate buffered aqueous solution, pH 7.6-7.8, are graduallyadded to the flask, along with a small amount of Dow-Corning antifoam.The flask is shaken occasionally until all the venom is in solution. 36grams of NaCl are added at this time. 2.0 ml of a freshly made 1.0%solution of CuSO are added and the flask is rotated vigorously. Eightyml of Superoxol (30% H are then slowly added while still rotating theflask. Eight ml of 38% formalin are then added while still rotating theflask. The contents are poured into a 4-liter volumetric flask and thebuffered solution is added to the volume line of the flask. Thecompleted preparation is poured into a 6-liter Florence flask, stopperedwith a gauze and cotton stopper which is covered with wax paper, andplaced in a 37C incubator.

The rate of detoxification is predictable but is checked by dailybioassay. This is done by injecting various amounts of the testsolution, brought to a constant volume of 0.5 ml with saline solution,into 20 gram CFW mice. via the intravenous route. When 0.5 ml of theundiluted solution produces death in approximately 50% of the mice, thesolution is taken from the incubator and the detoxification process isbrought to a quick stop by the addition of catalase (Armour 10). To makecertain that sufficient catalase has been added to destroy the excessperoxide, a smoldering wooden applicator stick is inserted into the neckof the flask. In the presence of a continuing reaction where free oxygenis given off, the wooden applicator stick will flame. To further insurethe cessation of detoxification, the pH of the solution maintained atabout 7.6 throughout the detoxification procedure, is reduced to about6.8. It should be noted that it may be necessary to add pellets orsolution of NaOH during the incubation period, since the pH tends todrop. When the detoxification procedure has been brought to an end,chlorotone is added, preliminary filtration is done through a K-2 Seitzclarifying filter, and finally sterilization is accomplished by passingthe solution through a large S-l Seitz filter. At that point thecomposition may be bottled and placed in a refrigerator without potencychanges. The proportions. as discussed above, are:

Catalase as required Chlorotone 8 g When the modified method of Boquetis applied to the Cram/us terrificus terrzfz'cus (Ctt) venom,detoxification is more rapid. To obtain a Ctt composition which willmeet the above requirements, the formula given above is altered byreducing in half the volume of hydrogen peroxide and formalin. Even withthis modified formula, the peroxide partial detoxification phase isbrought to a close usually within 15 hours. Then, after adding catalase,the Ctt solution is returned to the incubator at a pH of 7.6. Thedetoxification process continues more slowly and the results can becontrolled by mouse test. Within 2 to 3 days a satisfactory product isobtained, and the reaction can be concluded by changing the pH to 6.8,filtering and storing the composition at 4C. The bioassay procedure fortesting the Ctt composition is similar to that used for Naju flavacomposition.

Six rhesus monkeys were injected intracerebrally with approximately 50PD s (paralyzing dose of 50% of test animals) of Brunhilde virus.Twenty-four hours later, 3 of the animals received a single injection ofthe Naja flava derived composition (3/8 ml/Kg.), whereas the remaining 3animals were treated as controls and given no injections. On the 7th daypost-infection, the three untreated animals were either quadriplegic orheavily involved with paralysis, whereas the three treated animalsshowed no signs whatsoever of the disease. By the 9th day, when allthree untreated animals were quadriplegic, the disease was onlybeginning to be manifested in the three treated animals. In the treatedgroup, paralysis appeared on the 9th, 11th and 13th days, with anaverage incubation of l 1 days, as against a 7day average for theuntreated animals. As can be appreciated, this was a most severechallenge and the results show the marked effect of the neurotropiccomposition.

In a similar manner, 58 untreated control rhesus monkeys were challengedwith poliomyelitis and only one survived. By contrast, of 272 challengedand treated rhesus monkeys, 69 survived, 22 of them showing no sign ofthe disease, and 47 being, for the most part, lightly paralyzedsurvivors. Here again, the marked effect of the neurotropic compositionin the face of this severe challenge is demonstrated.

Table A shows the results of similar challenges when the composition isused on a therapeutic basis. After the animals were infected and groupswere determined by random selection, no animal was handled or receivedthe composition until there was a gross appearance of paralysis in theexperiment, i.e., when one or more animals in any group appeared to beparalyzed to a degree visible through the cage without manipulation.

Desiccatcd .\'ujufluru g Phosphate buffered aqueous On that day, wh chwas the 5th day after Infection, solution (pH 7.6) 3800 ml treatment wasmitlated on a predetermined basis. As 2 2 Tragg g can be seen from TableA, almost 50% of the treated CiiSO, r 1.0% i 3 m1 animals showed nogross signs of paralysis. Comparison 3,0 r g of the 45.8% O.K. survivorsin the treated groups with orma in 9 2) m 0 Phosphate buffered aqueous0% m the two control groups, reveals a marked effect solution us 4000 mlof the neurotropic composition on the disease.

TABLE A Composition RJ. (ml Composition Survivors*** Exp. No. per Kgmonkey No Mouse LD bod \\veight)** No rhesus ml infected No "/1 None(controls) 6 O 0 None (controls) 6 (l 0 1 1 12 TABLE A ContinuedComposition 0.1x.

R (ml Composition Sur\'i\'ors*** Exp. No. per Kg monkey No Mouse LDhodyueight) No rhesus ml infected No i 3 40 NF 0.6 0.4 6 2 4 40 NF 060.4 6 4 45.8 5 44 NF 0.3 0. l 6 3 6 44 NF 03 0.2 6 2 H 'l he doseindicated for each composition was administered on the 5th. 6th. 7th.8th and l lth days after injection.

** OK. Monkey showed no sign of polyiomyclitis.

In a similar experiment involving 99 treated animals and 24 untreatedcontrols, the composition administration was not initiated until the 6thday after the intracerebral injection. None of the 24 untreated controlssurvived. In the treated group, 17 animals survived, either lightlyparalyzed or without paralysis. Specific reference is made of these 123animals because the chal lenge was extremely severe, consisting ofintracerebrally injection of 50 PD per animal. Survivors occurred in thetreated group even when the composition was administered at a time whenparalysis was present in a number of the animals.

In a similar series of experiments 56,100 mice were injectedintracerebrally with pools of Lansing virus. One group was treated withthe composition and another group was treated with a placebo as acontrol. When the daily rate of paralysis and death was ploted for bothplacebo-controls and composition-treated groups, the controls followedthe straight line pattern within the expected limits. In the case of thetreated groups, a deviation of as much as 50% less involved and dyinganimals was noted between the 4th and 7th days post-infection. The twocurves, however, met either abruptly or gradually. There was nodifference in survivors in either of the groups at the end of the 30-dayexperiments which illustrates the requirement for continued treatment.

EXAMPLE 2 40 grams of desiccated Naja naja venom and 0.5 grams ofdesiccated Bungarus multicinctus venom are added to 3,600 ml ofphosphate buffered aqueous solution at a pH of 7.5. A trace amount ofsilicone antifoam (Dow-Corning) is added and the mixture is stirred todissolve the venom. 2 ml of 1% CP solution of copper sulfate is addedwith stirring. 80 ml of 30% hydrogen peroxide is added to the solution.The solution is placed in a volumetric flask and the phosphate bufferedaqueous solution is added to make 4,000 ml. The solution is incubated at37C, and the pH ismonitored. The pH is maintained at about 7.5 by theaddition of one normal sodium hydroxide solution as required. Aliquotsof the solution are tested daily for toxicity by inoculating 0.5 ml ofundiluted solution intraperitoneally per mouse in 20 gram mice. At theend of 14 days of detoxification 20 mice showed no deaths in 24 hours atthis level of inoculation. Also the detoxification is tested by giving adose of 5 ml to 350 gm guinea pigs and no deaths occurred in 24 hours.The bulk solution is then mixed with 3 mg of catalase per ml of solutionand placed in a cellulose acetate dialysis bag. The particular bag is aAPD millipore of 0.22 microns. The closed bag is placed in a dialyzingfluid of 1 part by weight of Sorensons buffer and 3 parts by weight of0.9% NaCl.

One volume of solution 15 dialyzed against nine volumes of dialyzingfluid. Finally. the solution was filtered through clarifying membranesand a final 0.22 micron filter and 1/10,000 concentration of merthiolatewas established and the pH was adjusted to 6.8 with 1N hydrochloricacid. The Semliki Forest virus test showed adequate plaque inhibition.The final product was tested for sterility and bioassayed for lack oftoxicity and safety.

It should be noted that there are several important differences betweenthe compositions of Examples 1 and 2. The formalin and chlorotone weredeleted from the Example 1 composition and the composition of Example 2was dialyzed. Also, the final filtration of the Example 2 compositionwas accomplished through a series of membranes with its final membranehaving an APD Millipore of 0.22 microns, and merthiolate was added to aconcentration of l/l0,000 parts. More significantly, the composition ofExample 2 contains the detoxified Bungarus venom and is atoxic ascompared to the composition of Example 1 which had residual toxicity.

EXAMPLE 3 Example 2 was repeated except that 1 gram of Bungarusmulticinctus was used.

EXAMPLE 4 The compositions of Examples 1, 2 and 3 were used in clinicalstudies. The composition of Example 1 shows the general interferenceeffects of the detoxified neurotoxic snake venom with Naja venom alone.The compositions of Examples 2 and 3 show improved results.

In order to interpret the results of the therapy with the compositions,it was necessary to classify the clinical state of deterioration of thepatients, since varying degrees of advancement of amyotrophic lateralsclerosis (ALS) was present at the time of treatment. It is also notedthat the specific disease may vary in its course within differentindividuals. This is true even in a disease, generally, as predictableas ALS. The'classification in Table 1 represents the degree of illnessin the patients in the study.

In Table 2, the therapeutic responses of the patients classified on thebasis of Table l are noted. A group of 41 ALS patients is presented. Ineach case a diagnosis of ALS has been made by a qualified neurologistand has been confirmed by a second neurologist or a recognized clinic.Data suggestive of a useful therapeutic ap proach are derived from anumber of patient survivals of up to 12 years. In evaluating patientsurvival it is, of course, necessary to consider the severity of thedisease at the time the therapy was initiated. The course of diseaseduring therapy is described in Table 2. in addition to survival therehave been improvements in muscle function, without reversal ofneurologic signs. A significant number of patients have responded, notonly in regard to survival, but in their state of comfort, maintenanceof function, and minimization of bulbar symptoms.

From Table 2 it may also be noted that therapeutic failures occurred inadvanced cases of ALS with appar- 10 or Example 3.

TABLE 1 Classification of Patients Clinical Involvement CLASS 1 Limitedinvolvement of several muscle groups. Usually no apparent or earlypyramidal tract signv No bulhar signs. Fasciculations may be prominent.Little or no upper motor neuron involvement. Paralysis limited andflaccid.

ll One or two limbs paralyzed. No bulhar signs. Pyramidal tract i(usually -lbut still early). Fasciculations vary from few and infrequentto many and frequently occurring. Little or no upper motor neuroneinvolvement.

lll Pyramidal tract involvement. Diffuse disease with paralysis andparesis. Fasciculations.

L'pper motor varies but Betz cells usually affected. Usually some bulharinvolvement. May ambulate with difficulty. May feed himself. This is anexplosive potential with almost certain. rapid deterioration.

l\ Severe. diffuse. flaccid paralysis with some spasticity. Pyramidaltract and bulhar imolvement. Fasciculations 2; Cannot amhulate nor feedhimself but may move a little when supported and with aid of a walker.

\' (a) Clinically not quite terminal but on basis of involvement plusduration of involvement may he considered terminal. Bulbar involvementvaries. usually at least moderate. Quadriplegia (b) Extreme bulharinvolvement with surprisingly little limb or trunk paralysis.Explosively near terminal stage because of anatomical involvement.

TABLE 2 Summary of ALS Patients Under MN Therapy (Treatment by injectionof .8 to L2 ml of composition every other day) Patient lllness Prior Classilication Example Duration Comments Number to MN Rs at time of MNM-N Used of M-N Rx (months Rx or years) l l l months Ill 1 8; 2 l 1 yrsis; Minimal pyramidal tract involvement.

Bulhar 9 months Remains ambulatory & bulhar negative Can still work 2 30months Ill 1 6+ years Function good in legs. Arms and hands Bulhar poorbut not useless. Depomedrol used (the single exception). Bulharquestionable. Bilateral pyramidal tract Death due to cardiovascularaccident.

3 24 months lll-lV l 6 years Rapid progression of ALS including hulbarBulbar -llinvolvement in 2 years prior to MN therapy. Bulhar continuedto advance under MN but very slowly. Bulbar death 4 19 months lll-l\' 1l3 months Marked pyramidal tract involvement.

Bulhar lnitial clinical prognosis for life about l2 mos. Lived 32months. Definite but temporary functional improvement under MN therapy.increased comfort. Bulbar death tranquil.

5 lZ-24 months llll\' l lo months Irregular use of MN. NeurologistBulhar states temporary improvement. then status quo" after one year.Contact lost.

6 lo months lll-lV 1 Lost contact Irregular dosage and schedule.

Bulhar after 8 Temporary objection functional months improvement threemonths and status quo after three months. No MN given after 8 months.

7 12-24 months Vh l l year Bulhar involvement extreme \vhen MNinitiated. This is only example functional response with this degree ofbulhar involvement. Arms 62 legs surprisingly good. Good improvement for6 months little skeletal muscle degeneration. About 7th months of Rsimprovement stopped;

Patient Number Illness Prior to M-l\' Rx (months or years) 5 months 5 V2months 15 months I 2 months 36 months 4 months 26 months I 3-16 months I4 months 2 years 2 years I year 2 years Classification at time of M-N RxIII Bulbar Ill Bulbar III Bulbar III Bulbar Ill Bulbar ll lll Bulbar IVV Bulbar -llll Bulbar TABLE 2 Continued Summary of ALS Patients UnderM-N Therapy (Treatment by injection of .8 to 1.2 ml of composition everyother day) Example M-N L'sed Duration of MN Rx 4 months 2 months I year8.: 8 months 1 year 4 months 19 months I year 1 year 2 I months 2% mos.

l month 5-6 months 3 months Comments Terminal bulbar. Arms & legs quitegood function. Bulhar death. Therapeutic failure.

Terminal bulbar. Bilateral pyramidal involvement. Fair limb function.Bulhar death. Therapeutic failure.

Diffuse progressive ALS. Short periods of definite functionalimprovement and then regression. M-N stoppped after I year and 8 months.Death about 60 days later. presumably ALS cause not known.

MN irregular patient did not follow directions. Pyramidal tractinvolved. History of CVS heart pulmonary embolism prostaticcomplications. Bulbar questionable Death probably bronchopneumonia Nopost-mortem.

Diffuse ALS rapidly progressing from time in early diagnosis. In spiteof sporadic brief periods of functional improvement. this patientcontinued on the inexorable course of ALS.

Relativelv slow disease process.

Patient s seen after about 7 months of experimental Rx withlsoprinosine.

Had definitely degenerated under Isoprinosine. With M-N showed temporaryimprovement and/or status quo. Off

M-N and degeneration was rapid. ALS death 2 months later.

Patient reacted well to M-N. Little or no degeneration in more than 1year of Rx. Complications: Prostatitis (old) and fracture of neck offemur pyramidal tract involved. C VA cause of death.

Diffuse. rapidly progressive ALS. Patient is now semi-ambulatory andshows no bulhar signs. Deceleration with this M-N Rx.

Reacted well during first three weeks M-N Rx then status quo. Diffusclyand severely involved when M-N initiated.

Terminal ALS with history of more than 3 years of diagnosis. Taperecording indicates functional improvement treatment (moves better andspeech can be understood). M-N stopped and patient after 41 days inhospital. died of probable bulbar ALS.

When M-N initiated. patient had deteriorated rapidly in that paresis ofone leg was followed by essentially complete paralysis of both legs(neurological). Since M-N Rx there has been questionable degenerationRate of ALS degeneration before and after M-N is important.

Initial proximation 0. right hand and left hand faciculations 4+.

Almost all bulhar symptoms. Tongue had complete atrophy. Within one weekTABLE 2 Continued Summary of ALS Patients Under M N Therapy (Treatmentby injection of .8 to 1.2 ml of composition every other day) PatientIllness Prior Classification Example Duration Comments Number to M N Rxat time of M-N M-N Used of M-N Rx (months Rx or years) of treatmentpro.\imation ws good with both hands. Subject now can open and closebuttons. After 12 days of treatment. there was complete use of thetongue and no choking.

4 to 5 years lll l\' 3 2 months Treatment improved speech swallowing andstrength of knees. The wallowcontinues to imprme. Fa culations wereeliminated after the first week of treatment.

0 months ll Ill 3 2 months Treatment produced a marked decrease in legcramps and allowed walking without a. lattice. Subject can pull slacksdown and up without assistance. Treatment improved the fine movement ofthe hands. Proximation is now okay as compared to 2+ prior to treatment.

13 2 years ll Ill 3 3-4 weeks lmproyement in swallowing alter 3 da \sBulbar of treatment and SUhJBLl now walks better without shuffling.

24 3: years ll 3 l month Treatment impro\ ed lasciculalions and linemmements ol hands.

8 months ll 3 l month Rapid impro ement in right forearm and tricepsafter 1 week of treatment 2o 2 years \'a & \'b 2 monthsSternocleidomastoid was initially tl.

Other neck muscles were initially U. Subject was quadriplegic. aphonicand the tongue was atrophic. Alter 3 weeks ol treatment. subject madesounds.

Maintained neck in upright position.

27 3 years l\ 3 2 months Within l month after treatment subject'sbreathing. hand movements and faseiculations were improved 2t 1: years\a 3 1 month After treatment. subjects breathing. tongue movement andswallowing improvement. Also there is slight improvement in legmovements.

2) 3 years \'a & \'b 3 2 months After treatment. subjects swallowingimproved.

3() l year ll 3 2 months After treatment, there was improvement in righthand grip and extension offingers. Proximation improved from 2+ to okay.

3l 3 years ll-lll 3 2 /2 months Prior deterioration of condition I hasbeen arrested by treatment and no further degeneration has taken place.

32 2 years \'b 3 1: mos. I Bulhar symptoms have improved with treatment.

3} 7-10 months I 3 2 months After treatment, the right foot dropimproved and fascieulatiorts improved from 4+ to 2+.

34 l 1: years \'b 3 1 mos. Swallowing improved with treatment andaphonia improved to some speech.

35 months I ll 3 2 months Slight improvement in strength of legs aftertreatment 36 3 years ll 3 2 months Treatment improved the line movementof hands. Proximation improved to H105? from 50 The strength in botharms improved and there was a decrease in fascieulation.

37 3: years ll Ill 3 l month Treatment improved the walking of thesubject.

38 l year Ill 3 2 months Swallowing was considerably improved Summary ofALS Patients Under M-N Therapy (Treatment by injection of .8 to 1.2 mlof composition every other day) Patient lllness Prior ClassificationExample Duration Comments Number to M-N Rx at time of M-N M-N Used ofM-N Rx (months Rx or years) after treatment. Sub ect can now eat solidfood as opposed to only being able to eat purecs prior to treatment.subject's walking changed from a shulTle to lifting up of his feet.Fusciculations significantly improved.

3) ti /2 years ill 3 2 months The weakness of legs made walking withouthelp impossible. Within month of treatment. subject could get out of bedwithout assistance and use the bathroom.

40 4 years lll l\' 3 2 months Slight improvement with treatment but atleast no further deterioration.

-ll 3% years \"a 3 3 months Slight improvement with treatment What isclaimed is:

l. A method of treatment of animals suffering from a progressivedegenerative neurological disease of motor nerve cell origins toneuromuscular junction, axones and nerve myelin sheaths comprisingadministering to the animal a disease mitigating amount of detoxified.and neurotropically active modified snake venom neurotoxin compositionwherein the said snake venom neurotoxin is derived from the venom of aspecies of the Bungarus genus or from the venom of a species of theBungarus genus and the Naja genus, and wherein said composition exhibitsat least a inhibition of plaques in the Semliki Forest virus test and abioassay shows that the composition is atoxic, as demonstrated byessentially no signs of toxicity in inoculation of laboratory animals.

2. The method of claim 1 wherein the said snake venom neurotoxin isderived from the venom of a spe cies of the Bungarus genus and the Najagenus.

3. The method of claim 1 wherein part of the said snake venom neurotoxinis derived from the venom of the species Crotalus terrlfi'cus.

4. The method of claim 1 wherein at least 75% inhibition of the saidplaques is exhibited.

5. The method of claim 1 wherein in humans the dosage of the compositionis from about 0.05 to 10 ml based on a 1% solution of the said modifiedneurotoxin per 150 lbs body weight.

6. The method of claim 5 wherein the dosage is from 0.4 to 3 ml.

7. The method of claim 5 wherein the dosage is administered in afrequency of from every other week to daily.

8. The method of claim 7 wherein the dosage is administered at leastweekly.

9. The method of claim 7 wherein the dosage is administered at least 3times a week.

10. The method of claim 7 wherein the administration is by subcutaneousor intramuscular injection.

11. The method of claim 2 wherein part of said snake venom neurotoxin isderived from the venom of Naja naja and Bungarus multicinctus..

but at leust no further deterioration.

12. The method of claim 2 wherein the ratio of Naja venom to Bungarusvenom is 400:] to 8:1.

13. The method of claim 12 wherein the ratio is 80zl to 40:1.

14. The method of claim 1 wherein the progressive degenerativeneurological disease is selected from amyotropic lateral sclerosis,multiple sclerosis, kuru, polymyositis, meningitides, musculardystrophy, and polyomyosities.

15. A composition comprising in an administrable form detoxified andneurotropically active modified snake venom neurotoxin where the saidsnake venom neurotoxin is derived from the venom of a species of theBungarus genus or from the venom of a species of the Bungarus genus andthe Naja genus, and wherein the composition exhibits at least a 30%inhibition of plaques in the Semliki Forest virus test and a bioassayshows that the composition is atoxic, as demonstrated by essentially nosigns of toxicity in inoculated laboratory animals.

16. The composition of claim 15 where the said snake venom neurotoxin isderived from the venom of a species of the Bungarus genus and the Najagenus.

17. The composition of claim 15 wherein part of the said snake venomneurotoxin is derived from the venom of the species Crotalus terrificus.

18. The composition of claim 15 wherein at least a inhibition of thesaid plaques is exhibited.

19. The composition of claim 15 wherein part of said snake venomneurotoxin is derived from the venom of the species Naja naja and thespecies Bungarus multicinctus.

20. The composition of claim 16 wherein the ratio of Naja venom toBungarus venom is 400:1 to 8:1.

21. The method of claim 20 wherein the ratio is :1

22. The method of producing the composition of claim 15 comprisingoxygenating at a pH of above 7 and a temperature of 15 to 40C the saidsnake venom until the venom is atoxic and dialyzing the resultingproduct.

1. A METHOD OF TREATMENT OF ANIMALS SUFFERING FROM A PROGRESSIVEDEGENERATIVE NEUROLOGICAL DISEASE OF MOTOR NERVE CELL ORIGINS TONEUTROMISCULAR JUNCTION, AXONES AND NERVE MYELIN SHEATHS COMPRISINGADMINISTERING TO THE ANIMAL A DESASE MITIGATING AMOUNT OF DETOXIFIED,AND NEUTROTROPICALLY ACTIVE MODIFIED SNAKE VENOM NEUROTOXIN COMPOSITIONWHEREIN THE SAID SNAKE VENOM NEUTROTOXIN IS DERIVED FROM THEVENOM OF ASPECIES OF THE BUNGARUS GENUS OR FROM THE VENOM OF A SPECIES OF THEBUNGARUS GENUS AND THE NAJA GENUS, AND WHEREIN SAID COMPOSITION EXHIBITSAT LEAST A 30% INHIBITION OF PLAQUES IN THE SEMLIKI FOREST VIRUS TESTAND A BIOASAY SHOWS THAT THE COMPOSITION IS ATOXIC, AS DEMONSTRATED BYESSENTIALLY NO SIGNS OF TOXICITY IN INOCULATION OF LABORATORY ANIMALS.2. The method of claim 1 wherein the said snake venom neurotoxin isderived from the venom of a species of the Bungarus genus and the Najagenus.
 3. The method of claim 1 wherein part of the said snake venomneurotoxin is derived from the venom of the species Crotalus terrificusterrificus.
 4. The method of claim 1 wherein at least 75% inhibition ofthe said plaques is exhibited.
 5. The method of claim 1 wherein inhumans the dosage of the composition is from about 0.05 to 10 ml basedon a 1% solution of the said modified neurotoxin per 150 lbs bodyweight.
 6. The method of claim 5 wherein the dosage is from 0.4 to 3 ml.7. The method of claim 5 wherein the dosage is administered in afrequency of from every other week to daily.
 8. The method of claim 7wherein the dosage is administered at least weekly.
 9. The method ofclaim 7 wherein the dosage is administered at least 3 times a week. 10.The method of claim 7 wherein the administration is by subcutaneous orintramuscular injection.
 11. The method of claim 2 wherein part of saidsnake venom neurotoxin is derived from the venom of Naja naja andBungarus multicinctus.
 12. The method of claim 2 wherein the ratio ofNaja venom to Bungarus venom is 400:1 to 8:1.
 13. The method of claim 12wherein the ratio is 80:1 to 40:1.
 14. The method of claim 1 wherein theprogressive degenerative neurological disease is selected fromamyotropic lateral sclerosis, multiple sclerosis, kuru, polymyositis,meningitides, muscular dystrophy, and polyomyosities.
 15. A compositioncomprising in an administrable form detoxified and neurotropicallyactive modified snake venom neurotoxin where the said snake venomneurotoxin is derived from the venom of a species of the Bungarus genusor from the venom of a species of the Bungarus genus and the Naja genus,and wherein the composition exhibits at least a 30% inhibition ofplaques in the Semliki Forest virus test and a bioassay shows that thecomposition is atoxic, as demonstrated by essentially no signs oftoxicity in inoculated laboratory animals.
 16. The composition of claim15 where the said snake venom neurotoxin is derived from the venom of aspecies of the Bungarus genus and the Naja genus.
 17. The composition ofclaim 15 wherein part of the said snake venom neurotoxin is derived fromthe venom of the species Crotalus terrificus terrificus.
 18. Thecomposition of claim 15 wherein at least a 75% inhibition of the saidplaques is exhibited.
 19. The composition of claim 15 wherein part ofsaid snake venom neurotoxin is derived from the vEnom of the speciesNaja naja and the species Bungarus multicinctus.
 20. The composition ofclaim 16 wherein the ratio of Naja venom to Bungarus venom is 400:1 to8:1.
 21. The method of claim 20 wherein the ratio is 80:1 to 40:1. 22.The method of producing the composition of claim 15 comprisingoxygenating at a pH of above 7 and a temperature of 15* to 40*C the saidsnake venom until the venom is atoxic and dialyzing the resultingproduct.